Automated tape libraries are a useful way of storing large amounts of information. Data is stored on dozens to hundreds of tape cartridges within the library. Robotic mechanisms move about the library moving cartridges from their storage slots to and from tape drives where the information can be accessed. The cartridges provide a convenient way to add new and remove blocks of information to and from the library. New blocks of prerecorded information are added to the library by inserting a new cartridge into an empty slot in the library and informing the library catalog of the new cartridge's location. Blocks of existing data can be removed for maintenance or archival by removing an existing cartridge.
Various mounting techniques have been used to accommodate the competing needs of the human users and robotic mechanisms to access the cartridges. In simple designs the users and robotic mechanisms access the cartridges and magazines from the same direction. This approach requires the robotic mechanisms to shut down while the user is inside the library to avoid man-machine collisions. More complicated library designs provide a Cartridge Access Port (CAP) that provide the users and robotic mechanisms two independent physical access paths to the same cartridge. Using the CAP approach, the robotic mechanisms access the cartridges from inside the library while the users access the same cartridges from the outside. This allows the robotic mechanisms to continue operating while a user is installing or removing cartridges. A drawback of this approach is that the user sees the cartridges from the tape side, not the label side. The user cannot determine if the proper cartridge is in the proper slot merely by looking. The user must remove the cartridge from the slot and turn it around to read the label. Finding a misplaced cartridge by this approach can be time consuming.
In larger tape libraries it is a common practice to group tape cartridges together into magazines. Each magazine allows the user to handle several cartridges simultaneously while always presenting the label side of the cartridges to the user. Using magazines, several cartridges may be added or removed from the library simultaneously. Magazines also allow cartridges to be added or removed individually.
The mounting apparatus used in a CAP approach must provide ease of magazine installation and removal by the users while providing accurate magazine positioning for the sake of the robotic mechanisms. One current mounting approach hangs the magazine from a rod inside the CAP. With this method, the user can hook and unhook the magazine to and from the rod using one hand on a handle provided on the front of the magazine. Magazine positioning is determined by the rod height, the CAP walls, and a closeable door on the user's side of the CAP.
In general, the existing mounting apparatuses work best when the magazines themselves are being installed and removed from the CAP. However, the existing apparatuses create problems for the user who wishes to install or remove more than one cartridge. As stated before, the magazine can be installed and removed with one hand. This leaves the users with a choice of inserting and removing the cartridges to and from the magazine with the free hand, or find a table to set the magazine down. Holding the magazine in one hand and manipulating the cartridges in the other is cumbersome. It also increases the potential for the users to drop and damage cartridges, or even the entire magazine. Moving to a table allows the user to use both hands to manipulate the cartridges, but it increases the time required to complete the task.
A preferred mounting apparatus would allow the magazine to be installed and completely removed from the CAP as the current apparatuses allow. It would also allow the magazine to be partially removed from, and yet still supported by the CAP so that the user can let go. Finally, from this partially removed position, the magazine must be oriented such that the user can easily insert and remove individual cartridges using both hands.